• Archives of Plastic Surgery
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• v.50 no.6
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• pp.568-572
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• 2023

Cutaneous squamous cell carcinoma (CSCC) overlying an arteriovenous fistula (AVF) is rare and presents unique challenges. This case report describes a method of fistula preservation after CSCC excision using a flow-through venous free flap. The saphenous vein of the venous flap was used as flow-through segment for AVF preservation. The flap was inserted along the dorsal aspect of the forearm wound and microvascular anastomosis of the arterial inflow was completed using a vein just proximal to the radiocephalic fistula anastomosis. Venous outflow was established by creating an end-to-end vascular anastomosis between the cephalic vein and the greater saphenous vein. A separate subcutaneous vein was used to provide a low-pressure outflow for the flap to avoid congestion. This case demonstrates an option for AVF preservation that has not been previously described. It also highlights the importance of a multidisciplinary approach for the safe treatment of CSCCs overlying AVFs.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.2
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• pp.187-196
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• 2013

A numerical model was developed to predict the density wave oscillation (DWO) in the furnace wall tubes of a fossil-fired once-through boiler. The transient flow fields in the tubes were obtained using a 1D finite volume method in the time domain. A header model was also implemented to simulate the parallel tube connection of the wall tubes. The inlet and outlet mass flow variation in one of the parallel tubes was examined after a heat perturbation to find the DWO. After successful verification with experimental results reported in literature, the developed model was applied to the wall tubes of a 700-MW boiler furnace. In contrast to the simulation of Takitani's experiment, in which the unstable power thresholds tended to rise in the reduced bypass channel flow, no remarkable changes were observed in the power thresholds in the parallel channel modeling of the wall tubes of the boiler furnace.

• Journal of Trauma and Injury
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• v.18 no.2
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• pp.172-174
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• 2005

Trauma of the vascular structure is not poplular event. In obstructive atherosclerotic vascular disease, we sometimes have needed bypass surgery. The long length subcutaneous prosthetic vascular graft are vulnerable to injury. But prosthetic vessel rupture after trauma has been rare report. A 68-year-old man was referred to Department of Emergency of the Gyeongsang National University Hospital. After he had had a blunt trauma, he found a newly appearing pulsating mass of 10 cm diameter on his right chest wall. The lesion had a turbulent blood flow in the cavity of the mass by ultrasonographic finding. The lesion was a rupture of superficial prosthetic vascular graft under the skin.

• Journal of Chest Surgery
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• v.10 no.2
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• pp.299-314
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• 1977

Clinical experience on 16 cases of open heart surgery under the extracorporeal circulation with mild or moderate hypothermia and partial hemodilution technique at the National Medical Center during the period from June 1976 to October 1977. Nine of sixteen were congenital heart disease and seven were acquired heart disease. The age of the patient ranged between 6 and 48 years. The body weight varied from 18.5kg to 60kg and body surface area 0. 79-1.70m2. The average priming volume of pump oxygenator was 2080 ml, which was consisted fresh ACD blood, buffered Hartmann`s solution, Mannitol, 50% dextrose in water and Vit. C. The average hemodilution rate was 27%. The average flow 2.3 L/min/m2 or 80 ml/min and the duration of perfusion varied from 31 min to 270 min with average of 107 min. The perfusion was carried out under the mild or moderate hypothermia using core cooling alone in 10 cases, core cooling and local myocardial cooling with $0-4^{\circ}C$ physiologic saline in 2 cases. From a hemodynamic point of view, the blood pressure dropped down around 80 mmHg after the initiation of perfusion follwed by increase to safety level and stable during the perfusion. The central venous pressure remained within normal limits. In most cases, hemoglobin and hematocrit decreased during and after the perfusion. Hemogiobin level was decreased, average of 20.6 %, hematocrit 18.6%, pletelets 55% postoperatively. Plasma hemoglobin increased moderately, from preperfusion average valve of 7.79 mg % to post-perfusion value of 54.7 mg %. Electrolytes changes during cardiopulmonary bypass showed definite hypokalemia but changes of Na, Ca were not definite. Arterial blood gas analysis during cardiopulmonary bypass suggested that the metabolic acidosis which was accompanied by respiratory alkalosis which was corrected postoperatively. As the opera tive complication, transient hemoglobinuria in 4 cases and neurological signs in 2 cases were all cured. There were 2 death cases and operative mortality rate was 12.5%.

• Journal of Chest Surgery
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• v.38 no.7 s.252
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• pp.504-506
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• 2005

Intracavitary coronary artery is variant anomalous entrance to right ventricular cavity of left anterior descending artery. Since the disease is extremely rare, there has not been any report of it in Korea and is only found in $0.2\~0.3\%$ of all CABG patients. It is very difficult to be diagnosed by preoperative coronary arteriography (CAG) and secure suture is needed for right ventriculotomy after CABG due to bleeding from right ventricle. Horizontal mattress suture with pledget has been recommended but, it could compress the myocardium surrounding ventriculotomy and result in disturbed flow of left anterior descending artery branch and perforating artery. So we used simple interrupted suture and the patient was recovered as other CABG patients without complications.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.3
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• pp.691-705
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• 2012

Buffer overflow vulnerability is the most representative one that an attack method and its countermeasure is frequently developed and changed. This vulnerability is still one of the most critical threat since it was firstly introduced in middle of 1990s. Shellcode is a machine code which can be used in buffer overflow attack. Attackers make the shellcode for their own purposes and insert it into target host's memory space, then manipulate EIP(Extended Instruction Pointer) to intercept control flow of the target host system. Therefore, a lot of research to defend have been studied, and attackers also have done many research to bypass security measures designed for the shellcode defense. In this paper, we investigate shellcode defense and attack techniques briefly and we propose our new methodology which can hide shellcode in the 24bit BMP image. With this proposed technique, we can easily hide any shellcode executable and we can bypass the current detection and prevention techniques.

• Journal of Chest Surgery
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• v.37 no.2
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• pp.131-138
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• 2004

High-flow gas insufflation to get a bloodless field during off-pump coronary artery bypass may have adverse effects on the coronary endothelium. This study was designed (1) to elucidate the effect of carbon dioxide gas insufflations on the coronary endothelium at different flow rates and (2) to assess the protective effect of humidifcation against the coronary endothelial damage. Material and Method: In nine pigs, the left anterior descending coronary artery (LAD) was exposed after a median sternotomy. The LAD was divided into 4 segments and a coronary arteriotomy was made in each LAD segment in the beating heart. The far distal arteriotomy was exposed to room air for 10 minutes and was harvested as a control. Non-humidified carbon dioxide gas at a continuous flow rate of 5 L/min (Group I), humidified carbon dioxide gas at a continuous flow rate of 5 L/min (Group II), and humidified carbon dioxide gas at a continuous flow rate of 10 L/min (Group III) were insufflated for 10 minutes on each coronary arteriotomy site, respectively. After harvesting the coronary segments, hematoxylin-eosin staining, elastic fiber staining, and immunostaining with a CD34 monoclonal antibody were performed to evaluate the depth of endothelial damage and to count the residual endothelial cells, Result: In all three groups (Group I, II, and III), internal elastic laminae were preserved, however, the endothelial layers were significantly damaged by carbon dioxide gas insufflation. The mean percentages of remaining endothelial cells were 20,9$\pm$16.7%, 39.3$\pm$19.6%, and 6.8$\pm$5.3%, in groups I, II, and III, respectively. The percentages of remaining cells were significantly higher in group II than in groups I and III (p=0.008). The percentages of remaining cells were significantly higher in group I than in group III (p=0.008). Conclusions: The harmful effect of carbon dioxide gas insufflation on the coronary endothelium was dependent on the flow rate. The addition of humidification did not protect the coronary endothelium from denudation injury caused by high flow carbon dioxide gas insufflations.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.4
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• pp.434-443
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• 2014

A turbo fan engine performance analysis and the optimization using particle swarm optimization(PSO) algorithm have been conducted to investigate the effects of major performance design parameters of an aircraft gas turbine engine. The FJ44-2C turbofan engine, which is widely used in the small business jet, CJ2 has been selected as the basic model. The design parameters consists of the bypass ratio, burner exit temperature, HP compressor ratio, fan inlet mass flow, and nozzle cooling air ratio. The sensitivity analysis of the parameters has been evaluated and the optimization of the parameters has been performed to achieve high net thrust or low specific fuel consumption.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.1
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• pp.73-80
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• 2018

Intermittent duty of emergency generator has problems emitting large quantities of PM and NOx in exhaust gas. The aim of this study is to propose DPF system which can be applied to medium-large emergency generators. The system is composed of soot dust collector, silencer and filter trap, which is designed to reduce PM emissions at the emergency generator start-up. The pneumatic system controls a flow direction of exhaust gas to pass through the soot collector and filter trap until the engine reaches complete combustion condition. An experiment is performed to measure PM content and concentration to analyze the performance and characteristics of the proposed system.

• Journal of Chest Surgery
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• v.10 no.2
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• pp.250-267
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• 1977

Open heart surgery has been performed on 20 patients, using hemodilution principle under the moderate hypothermia from Dec. 1975 through Aug. 1977 at the Department of Thoracic and Cardiovascular Surgery, Kyungpook National University School of Medicine. All these patients, body surface area ranged from 0.53 to 1.67$M^2$, were divided into two groups as a child group [below 15 yrs] and a adult group[above 15 yrs]. The oxygenator were primed with fresh ACD blood, 5 per cent dextrose, Hartmann`s solution, 15 per cent mannitol, sodium bicarbonate, dexamethasone and antibiotics. The average flow rate was 2.0 L/$M^2$/min. in child group and 2.3L/$M^2$/min. in adult group. The degree of hemodilution in child and adult group was 30.7% and 29.3% respectively. The minimal value of rectal temperature was $30.84{\pm}0.7^{\circ}C.$, in child group and $30.0{\pm}1.5^{\circ}C.$, in adult group. We studied the changes of hemodynamic status, blood components, electrolyte, acid-base status. blood lactic acid and urine output during and after cardiopulmonary bypass.